The existing display panels usually will setting outputting voltage after manufacturing, and it let the display panel could achieve to a certain brightness when outputting a certain voltage. However, the actual output voltage of the display panel usually will larger or smaller than the correspondingly setting voltage—which is potential deviation, such that affect the display effect. In order to solve this problem, in the present the technology is for detecting potential of display panel by potential detecting IC, and then comparing the detecting potential and the needs potential of normal display, if these two potentials are difference, inputting the correspondingly potential compensation value for regulating the display panel. It collude ensure display effect of display panel. However, if the potential deviation of display panel is more than the regulation range of the display panel, it could not provide a effectively compensation regulating.